[Solved]-Receiving The type java.lang.CharSequence cannot be resolved. error message with Java 8 JDK-eclipse

adding just language="groovy" in the jrxml worked for me.

<jasperreport 
    xmlns="http://jasperreports.sourceforge.net/jasperreports" 
    xmlns:xsi="http://www.w3.org/2001/xmlschema-instance" 
    xsi:schemalocation="http://jasperreports.sourceforge.net/jasperreports http://jasperreports.sourceforge.net/xsd/jasperreport.xsd" 
    name="jasper_report_template" **language="groovy"** 
    pagewidth="100" pageheight="100" columnwidth="10" 
    leftmargin="20" rightmargin="20" topmargin="20" bottommargin="20" 
>

as all said just upgrade jetty server

if you are using maven

go to jetty plugin and update it to

<plugin>
    <groupid>org.eclipse.jetty</groupid>
    <artifactid>jetty-maven-plugin</artifactid>
    <version>9.3.0.v20150612</version>
    <configuration>
        <scanintervalseconds>3</scanintervalseconds>
        <httpconnector>
            <port>${jetty.port}</port>
            <idletimeout>60000</idletimeout>
        </httpconnector>
        <stopkey>foo</stopkey>
        <stopport>${jetty.stop.port}</stopport>
    </configuration>
</plugin>

jetty 7 (and lower) probably does not support java 8. in java 8 some changes to classes were made, causing the jsp compilation failure.

related question (same exception): unable to compile class for jsp: the type java.util.map$entry cannot be resolved. it is indirectly referenced from required .class files

related problem in manifoldcf (same exception): https://issues.apache.org/jira/browse/connectors-938

at least jetty 9.2 supports java 8: https://webtide.com/jetty-9-2-0-released/ http://www.eclipse.org/jetty/documentation/current/what-jetty-version.html